The present invention relates to a method of controlling controlled elements of a rail vehicle, in particular a method of controlling elements intended to improve the comfort of passengers, and also relates to a control device for controlled elements which is adapted to implement the method.
At present there are two main techniques for controlling controlled elements of a rail vehicle which are essentially used to control controlled elements controlling the inclination of a tilting vehicle.
A first technique consists of measuring inertial values, in particular the transverse acceleration, the roll velocity of the vehicle and possibly the yaw velocity of the bogie, calculating from those values geometrical characteristics descriptive of the track on which the vehicle is traveling, and generating control set points from those characteristics, such as the angle of inclination in the case of a tilting train.
The above technique generates relatively accurate angle set points. It has a number of drawbacks, however, in particular because the inclination of the vehicle is out of phase with the curves negotiated by the vehicle in that it does not take account of the time-delay inherent to the processing of the inertial values or the time-delay generated by operation of the tilt drive systems equipping each body of the vehicle and to which the angle set points are transmitted.
The time-delay can be clearly perceptible at speeds from 160 kph in the case of a train with a motor car at the front.
Another prior art technique, which was developed to overcome the above drawback, consists of equipping the rail tracks with beacons for accurately determining the location of the rail vehicle on the track on which it is travelling and transmitting control set points, in particular inclination angle set points in the case of a tilt system, in advance, to compensate the time-delays inherent to the operation of such systems.
The above tilting technique effectively compensates the centrifugal force to which the passengers on the vehicle are subjected because tilting can be applied in phase with the curve being negotiated. It nevertheless has the drawback of making it necessary to equip with beacons all rail tracks of a rail network on which operation in tilt mode is authorized, and its cost is therefore prohibitive.
What is more, it cannot be used on sections of the network that are not equipped with the beacons.
The object of the invention is to overcome these drawbacks by proposing a method of controlling controlled elements of a rail vehicle which enables the controlled elements to be controlled in advance so that their reaction is in phase with the geometry of the rail track, without necessitating additional rail track equipment, in order to be simple and economical to put into practice.
The invention therefore provides a method of controlling controlled elements of a rail vehicle, in which method descriptive geometrical characteristics of the rail track are calculated by measuring inertial values on board the vehicle and control set points for said controlled elements are generated from said characteristics, characterized in that it includes the steps of:
determining the location of the vehicle on the rail track on which it is travelling by comparing calculated geometrical characteristics with geometrical characteristics stored in a database and obtained by a learning process;
extracting geometrical characteristics corresponding to the next curve from the database; and
generating control set points for the controlled elements in advance from the extracted characteristics.
The method according to the invention can further include one or more of the following features, individually or in all technically feasible combinations:
before generating the control set point(s) of the controlled elements, at least one of the geometrical characteristics calculated is compared to a window for validating the location of the rail vehicle generated from the respective data extracted from the database and corresponding to the presumed location of the rail vehicle and in that if there is no correspondence between the geometrical characteristic(s) calculated and the validation window control set point(s) for the controlled elements are generated from the calculated geometrical characteristics;
determining the location of the vehicle includes the steps of identifying the rail track on which the vehicle is travelling by comparing the geometrical characteristics calculated with characteristics stored in the database and calculating the distance to the next curve from a measured speed of the rail vehicle and the length of a straight section preceding said curve extracted from the database;
at least on leaving each curve the location of the vehicle on the rail track is corrected by comparing geometrical characteristics calculated while negotiating the curve with characteristics stored in the database;
it further includes a step of transmitting the control set point(s) to the controlled elements equipping each car of the rail vehicle at times enabling compensation of the time-delays generated in the operation of said controlled elements and depending on the location of each car in the vehicle;
the controlled elements are elements of an active suspension;
the controlled elements are elements controlling the position of orientable axles of a bogie;
the controlled elements are elements controlling the tilt of a tilting rail vehicle and the control set points are inclination angle set points;
a weighting coefficient for the inclination of the rail vehicle for each curve extracted from the database is applied to the angle set point(s).
The invention also provides a device for controlling controlled elements of a rail vehicle, of the type including means for measuring inertial values and a computer adapted to calculate descriptive geometrical characteristics of the rail track on which the vehicle is travelling from the measured inertial values and to generate control set points for the controlled elements from the geometrical characteristics calculated, characterized in that the computer includes means for determining the location of the rail vehicle by comparing the geometrical characteristics calculated with geometrical characteristics stored in a database stored in the computer and obtained beforehand by a learning process, the inertial values used to generate the control set point or points corresponding to the next curve being generated in advance from characteristics of that curve extracted from the database in order to control said controlled elements in phase with the curve.
The device according to the invention can further include one or more of the following features, individually or in all technically feasible combinations:
the controlled elements are elements controlling the inclination of a tilting rail vehicle and the control set points are inclination angle set points for the rail vehicle;
the controlled elements are elements of an active transverse suspension;
the controlled elements are elements controlling the position of orientable axles of a bogie.